WASHINGTON — A man who drove up to a White House gate and refused to leave was arrested on Saturday, the Secret Service said, less than 24 hours after another man jumped the fence and made it all the way into the presidential residence before being apprehended. The president and first family were not at home.

The second incident started Saturday afternoon when a man approached one of the White House gates on foot, Secret Service spokesman Ed Donovan said. He later showed up at another gate in a car and pulled into the vehicle screening area. When the man refused to leave, he was placed under arrest and charged with unlawful entry. Officials have not released his identity.

Bomb technicians, fully suited, could be seen looking through a white four-door sedan with New Jersey plates and pulling out what appeared to be keys. Streets near the White House were temporarily closed as officers responded, but the White House was not locked down.

It wasn't immediately clear who the man was or why he was trying to enter the White House. President Barack Obama, his wife and daughters were at Camp David, the presidential retreat in Maryland where the first family was spending the weekend.

There were no signs that Saturday's arrest was related to the security breach the night before. But the pair of incidents in short succession heightened concerns about security at the White House, one of the most heavily protected buildings in the world.

Just minutes after Obama and his daughters had departed by helicopter Friday evening, a 42-year-old man hopped over the fence and darted across the lawn, ignoring officers' commands to stop, Donovan said. He managed to get through the doors of the North Portico, the grand, columned entrance that looks out over Pennsylvania Avenue.

The Secret Service identified the suspect as Omar Gonzalez of Copperas Cove, Texas. He was charged with unlawful entry into the White House complex and transported to a nearby hospital complaining of chest pain.

On a quiet cul-de-sac about an hour's drive from Waco, Texas, where Gonzalez was last known to have lived, former neighbors said he moved out roughly two years ago, explaining only that he had to get out of Copperas Cove, which sits next to the Fort Hood Army post.

Sgt. 1st Class David Haslach, who lives two doors down from Gonzalez's former home, said Gonzalez had been in the U.S. military and told Haslach he had received a medical discharge. He and another former neighbor, Elke Warner, both recalled him seeming paranoid in the months before he left town.

"At the end, he got so weird. He had motion detector lights put in," Warner said. She added that she last saw Gonzalez about a year and a half ago at a nearby camp site, where he was apparently living with his two dogs

The breach triggered a rare evacuation of much of the White House, with Secret Service officers drawing their guns as they rushed staffers and journalists out a side door.

Officials said Gonzalez appeared as he was running to be unarmed — potentially one reason why agents didn't shoot him or dispatch service dogs to stop him — and agents who searched him found no weapons.

The embarrassing incident comes at a difficult time for the Secret Service, which is still struggling to rehabilitate its image following a series of allegations of misconduct by agents in recent years, including agents on Obama's detail.

The Secret Service has struggled in recent years to strike the appropriate balance between ensuring the first family's security and preserving the public's access to the White House grounds. Once open to vehicles, the stretch of Pennsylvania Avenue in front of the White House was confined to pedestrians after the Oklahoma City bombing, but officials have been reluctant to restrict access to the area further.

Last year, a 34-year-old dental hygienist tried to ram her car through a White House barrier before leading police on a chase that ended with her being killed. Her 1-year-old daughter was in the car but escaped serious injury.

Pablo Martinez Monsivais in Washington and Terry Wallace in Copperas Cove, Texas contributed to this report. Reach Josh Lederman on Twitter at http://twitter.com/joshledermanAP